The present invention relates to reciprocatory internal combustion engines.
According to the present invention there is provided a three-cylinder four-stroke radial internal combustion engine in which two of the cylinders are diameterically opposed and the axis of the third cylinder is at right angles to the axes of the two opposed cylinders.
Also according to the invention, there is provided a four-stroke internal combustion engine having a rotary output shaft and at least one set of three cylinders having a reciprocatory piston in each cylinder, characterised in that the set of three cylinders is associated with one eccentric portion of the output shaft, the first and third cylinders are opposed cylinders on opposite sides of the output shaft and having their axes perpendicular to that of the second cylinder, a reciprocatory counterweight connected to the second piston is guided for reciprocation in the direction of the axis of the second cylinder, drive means interconnect the eccentric portion of the output shaft with the pistons of the three cylinders and with the reciprocatory weight, and rotary counterweight means on the shaft substantially counterbalance the rotating mass effectively formed by the first and third pistons oscillating in quadrature with the second piston and reciprocatory counterweight.
The invention further provides a four-stroke radial internal combustion engine having at least one set of only three cylinders in which two of the cylinders are diametrically opposed and the axis of the third cylinder is at right angles to the axes of the two opposed cylinders, a reciprocatory piston in each cylinder, an output shaft having an eccentric portion, driving means interconnecting the said eccentric portion with the three pistons and forming with the two opposed pistons a first reciprocatory mass and with the third piston a second reciprocatory mass, the directions of reciprocation of the first and second masses being at right angles, the second mass being weighted to be equal to the first mass, the two masses being arranged to be oscillated in quadrature by the eccentric portion and the output shaft having balancing means for counterbalancing the effective rotating mass formed by the two said masses oscillating in quadrature.